diff -u b/pagerer.module b/pagerer.module
--- b/pagerer.module
+++ b/pagerer.module
@@ -105,7 +105,7 @@
   // Preprocess through the multipane pager plugin.
   $pager
     ->setRouteName($variables['pager']['#route_name'])
-    ->setRouteParameters(isset($variables['pager']['#route_parameters']) ? $variables['pager']['#route_parameters'] : []);
+    ->setRouteParameters($variables['pager']['#route_parameters'] ?? []);
   \Drupal::service('pagerer.style.manager')
     ->createInstance('multipane', $variables['pager']['#config'])
     ->setPager($pager)
@@ -175,7 +175,7 @@
   // Let the style plugin do its own preprocessing.
   $pager
     ->setRouteName($variables['pager']['#route_name'])
-    ->setRouteParameters(isset($variables['pager']['#route_parameters']) ? $variables['pager']['#route_parameters'] : []);
+    ->setRouteParameters($variables['pager']['#route_parameters'] ?? []);
   \Drupal::service('pagerer.style.manager')
     ->createInstance($variables['pager']['#style'], $variables['pager']['#config'])
     ->setPager($pager)
diff -u b/src/Plugin/pagerer/PagererStyleBase.php b/src/Plugin/pagerer/PagererStyleBase.php
--- b/src/Plugin/pagerer/PagererStyleBase.php
+++ b/src/Plugin/pagerer/PagererStyleBase.php
@@ -6,8 +6,8 @@
 use Drupal\Component\Utility\NestedArray;
 use Drupal\Component\Utility\Random;
 use Drupal\Component\Utility\UrlHelper;
-use Drupal\Core\Config\TypedConfigManager;
 use Drupal\Core\Config\ConfigFactoryInterface;
+use Drupal\Core\Config\TypedConfigManager;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Pager\PagerManagerInterface;
 use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
only in patch2:
unchanged:
--- a/pagerer_example/src/Controller/PagererExampleController.php
+++ b/pagerer_example/src/Controller/PagererExampleController.php
@@ -3,12 +3,64 @@
 namespace Drupal\pagerer_example\Controller;
 
 use Drupal\Core\Controller\ControllerBase;
+use Drupal\Core\Database\Connection;
+use Drupal\Core\Extension\ModuleExtensionList;
+use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
  * Controller class for Pagerer example.
  */
 class PagererExampleController extends ControllerBase {
 
+  /**
+   * Active database connection.
+   *
+   * @var \Drupal\Core\Database\Connection
+   */
+  protected $database;
+
+  /**
+   * The module extension list.
+   *
+   * @var \Drupal\Core\Extension\ModuleExtensionList
+   */
+  protected $moduleExtensionList;
+
+  /**
+   * The module extension list.
+   *
+   * @var \Drupal\pagerer\Plugin\PagererStyleManager
+   */
+  protected $styleManager;
+
+  /**
+   * Constructs a MessageController object.
+   *
+   * @param \Drupal\Core\Database\Connection $database
+   *   A database connection.
+   * @param \Drupal\Core\Extension\ModuleExtensionList $extension_list_module
+   *   The module extension list.
+   * @param \Drupal\pagerer\Plugin\PagererStyleManager $style_manager
+   *   The plugin manager for Pagerer style plugins.
+   */
+  public function __construct(Connection $database, ModuleExtensionList $extension_list_module, PagererStyleManager $style_manager) {
+    $this->database = $database;
+    $this->moduleExtensionList = $extension_list_module;
+    $this->styleManager = $style_manager;
+
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container): self {
+    return new static(
+      $container->get('database'),
+      $container->get('extension.list.module'),
+      $container->get('pagerer.style.manager')
+    );
+  }
+
   /**
    * Get pagerer example page title.
    *
@@ -17,7 +69,7 @@ class PagererExampleController extends ControllerBase {
    */
   public function examplePageTitle(): string {
     // Set the page title to show current Pagerer version.
-    $module_info = \Drupal::service('extension.list.module')->getExtensionInfo('pagerer');
+    $module_info = $this->moduleExtensionList->getExtensionInfo('pagerer');
     return $this->t("Pagerer @version - example page", ['@version' => $module_info['version'] ?? 'dev']);
   }
 
@@ -35,7 +87,7 @@ class PagererExampleController extends ControllerBase {
       ['data' => 'type'],
       ['data' => 'timestamp'],
     ];
-    $query_0 = \Drupal::database()->select('watchdog', 'd')->extend('Drupal\Core\Database\Query\PagerSelectExtender')->element(0);
+    $query_0 = $this->database->select('watchdog', 'd')->extend('Drupal\Core\Database\Query\PagerSelectExtender')->element(0);
     $result_0 = $query_0
       ->fields('d', ['wid', 'type', 'timestamp'])
       ->limit(5)
@@ -51,7 +103,7 @@ class PagererExampleController extends ControllerBase {
       ['data' => 'collection'],
       ['data' => 'name'],
     ];
-    $query_1 = \Drupal::database()->select('key_value', 'd')->extend('Drupal\Core\Database\Query\PagerSelectExtender')->element(1);
+    $query_1 = $this->database->select('key_value', 'd')->extend('Drupal\Core\Database\Query\PagerSelectExtender')->element(1);
     $result_1 = $query_1
       ->fields('d', ['collection', 'name'])
       ->limit(10)
@@ -68,7 +120,7 @@ class PagererExampleController extends ControllerBase {
       ['data' => 'name'],
       ['data' => 'path'],
     ];
-    $query_2 = \Drupal::database()->select('router', 'd')->extend('Drupal\Core\Database\Query\PagerSelectExtender')->element(2);
+    $query_2 = $this->database->select('router', 'd')->extend('Drupal\Core\Database\Query\PagerSelectExtender')->element(2);
     $result_2 = $query_2
       ->fields('d', ['name', 'path'])
       ->limit(5)
@@ -80,7 +132,7 @@ class PagererExampleController extends ControllerBase {
     }
 
     // Get the available pagerer style plugins.
-    $plugin_definitions = \Drupal::service('pagerer.style.manager')->getDefinitions();
+    $plugin_definitions = $this->styleManager->getDefinitions();
     // Put the 'standard' plugin on top.
     if (isset($plugin_definitions['standard'])) {
       $standard = $plugin_definitions['standard'];
only in patch2:
unchanged:
--- a/src/Entity/PagererPreset.php
+++ b/src/Entity/PagererPreset.php
@@ -81,7 +81,7 @@ class PagererPreset extends ConfigEntityBase {
       if (is_array($errors)) {
         foreach ($errors as $key => $error) {
           if ($error === 'missing schema') {
-            list(, $element) = explode(':', $key);
+            [, $element] = explode(':', $key);
             $this->unsetPaneData($pane, "config.$element");
           }
         }
only in patch2:
unchanged:
--- a/src/Form/PagererConfigForm.php
+++ b/src/Form/PagererConfigForm.php
@@ -6,8 +6,8 @@ use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Entity\EntityListBuilderInterface;
 use Drupal\Core\Form\ConfigFormBase;
 use Drupal\Core\Form\FormStateInterface;
-use Drupal\Core\Render\ElementInfoManagerInterface;
 use Drupal\Core\Pager\PagerManagerInterface;
+use Drupal\Core\Render\ElementInfoManagerInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
only in patch2:
unchanged:
--- a/src/PagererManager.php
+++ b/src/PagererManager.php
@@ -3,9 +3,9 @@
 namespace Drupal\pagerer;
 
 use Drupal\Core\Config\ConfigFactoryInterface;
-use Drupal\Core\Url;
 use Drupal\Core\Pager\PagerManager;
 use Drupal\Core\Pager\PagerParametersInterface;
+use Drupal\Core\Url;
 
 /**
  * Provides a manager for Pagerer, as an extension of core's PagerManager.
only in patch2:
unchanged:
--- a/src/PagererPresetListBuilder.php
+++ b/src/PagererPresetListBuilder.php
@@ -3,8 +3,8 @@
 namespace Drupal\pagerer;
 
 use Drupal\Core\Config\Entity\ConfigEntityListBuilder;
-use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Entity\EntityHandlerInterface;
+use Drupal\Core\Entity\EntityInterface;
 
 /**
  * Provides a listing of Pagerer presets.
only in patch2:
unchanged:
--- a/src/Plugin/pagerer/Multipane.php
+++ b/src/Plugin/pagerer/Multipane.php
@@ -5,8 +5,8 @@ namespace Drupal\pagerer\Plugin\pagerer;
 use Drupal\Component\Utility\NestedArray;
 use Drupal\Core\Cache\CacheableMetadata;
 use Drupal\Core\Plugin\PluginBase;
-use Drupal\pagerer\Pagerer;
 use Drupal\pagerer\Entity\PagererPreset;
+use Drupal\pagerer\Pagerer;
 use Drupal\pagerer\Plugin\PagererStyleInterface;
 
 /**
@@ -70,9 +70,9 @@ class Multipane extends PluginBase implements PagererStyleInterface {
     // Check if pager is needed; if not, return immediately.
     // It is the lowest required number of pages in any of the panes.
     $page_restriction = min(
-      isset($this->configuration['panes']['left']['config']['display_restriction']) ? $this->configuration['panes']['left']['config']['display_restriction'] : 2,
-      isset($this->configuration['panes']['center']['config']['display_restriction']) ? $this->configuration['panes']['center']['config']['display_restriction'] : 2,
-      isset($this->configuration['panes']['right']['config']['display_restriction']) ? $this->configuration['panes']['right']['config']['display_restriction'] : 2
+      $this->configuration['panes']['left']['config']['display_restriction'] ?? 2,
+      $this->configuration['panes']['center']['config']['display_restriction'] ?? 2,
+      $this->configuration['panes']['right']['config']['display_restriction'] ?? 2
     );
     if ($this->pager->getTotalPages() < $page_restriction) {
       return;
@@ -86,7 +86,7 @@ class Multipane extends PluginBase implements PagererStyleInterface {
           '#theme' => 'pagerer_base',
           '#style' => $this->configuration['panes'][$pane]['style'],
           '#route_name' => $variables['pager']['#route_name'],
-          '#route_parameters' => isset($variables['pager']['#route_parameters']) ? $variables['pager']['#route_parameters'] : [],
+          '#route_parameters' => $variables['pager']['#route_parameters'] ?? [],
           '#element' => $variables['pager']['#element'],
           '#parameters' => $variables['pager']['#parameters'],
           '#config' => $this->configuration['panes'][$pane]['config'],